With Check Engine Light

1. Perform the following safety precautions to start and run vehicle tests.
a. Apply parking brake.
b. Place gear select lever into PARK position (NEUTRAL on manual transmission).
c. Block drive wheels.
NOTE: Correct results of the Quick tests are dependent on the proper operation of related non-EEC components. It may be necessary to disconnect or disassemble harness connector assemblies to do some of the inspections. Pin locations should be noted prior to disassembly.
2. Inspect the air cleaner and inlet ducting.
3. Check all engine vacuum hoses for damage, leaks, cracks, blockage, proper routing, etc.
4. Check EEC system wiring harness for proper connections, bent or broken pins, corrosion, loose wires, proper routing, etc.
5. Check the Electronic Control Assembly (ECA), sensors, and actuators for physical damage.
6. Check the engine coolant for proper level.
7. Check the transmission fluid level and quality.
8. Make all necessary repairs prior to continuing with test preparation.
9. Turn OFF all electrical loads (radio, lights, A/C-heater blower fans, etc.)
10. Turn the ignition switch OFF.

NOTE: If check engine (MIL) light flashes continuously prior to equipment hookup, STI1 - STI to ECA

Diagnostic Connector (STO/STI):

11. Jumper EEC STI to engine ground.
12. Continue with Key On Engine Off Self Test. QT5-QT6 - Key On Engine Off Test/Erase and Retest